I’ve recently embedded the Squirrel Programming Language into Windriver’s VxWorks 6.9. This allows me to run scripts (.nut) from any mounted file system. I have exported a few critical VxWorks primitives to the Squirrel language, i.e. peek(), poke() memory addresses, mutex locks, and shared object access. This allows me to bit bang peripherals chips, and processors, without recompiling anything. Also, it allows testers to run scripts at a deeper level of interaction with the realtime / kernel code without having to have a VxWorks developer license.
Read all about Squirrel here. It’s an “improved” Lua depending on your perspective.